We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure coreplatform@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
At present, the study on autonomous unmanned ground vehicle navigation in an unstructured environment is still facing great challenges and is of great significance in scenarios where search and rescue robots, planetary exploration robots, and agricultural robots are needed. In this paper, we proposed an autonomous navigation method for unstructured environments based on terrain constraints. Efficient path search and trajectory optimization on octree map are proposed to generate trajectories, which can effectively avoid various obstacles in off-road environments, such as dynamic obstacles and negative obstacles, to reach the specified destination. We have conducted empirical experiments in both simulated and real environments, and the results show that our approach achieved superior performance in dynamic obstacle avoidance tasks and mapless navigation tasks compared to the traditional 2-dimensional or 2.5-dimensional navigation methods.
Depressive symptoms and cognitive impairment often coexisted in the elderly. This study investigates the effect of late-life depressive symptoms on risk of mild cognitive impairment (MCI).
Methods
A total of 14,231 dementia- and MCI free participants aged 60+ from the Survey of Health, Ageing, and Retirement in Europe were followed-up for 10 years to detect incident MCI. MCI was defined as 1.5 standard deviation (SD) below the mean of the standardized global cognition score. Depressive symptoms were assessed by a 12-item Europe-depression scale (EURO-D). Severity of depressive symptoms was grouped as: no/minimal (score 0–3), moderate (score 4–5), and severe (score 6–12). Significant depressive symptoms (SDSs) were defined as EURO-D score ≥ 4.
Results
During an average of 8.2 (SD = 2.4)-year follow-up, 1,352 (9.50%) incident MCI cases were identified. SDSs were related to higher MCI risk (hazard ratio [HR] = 1.26, 95% confidence intervals [CI]: 1.10–1.44) in total population, individuals aged 70+ (HR = 1.35, 95% CI: 1.14–1.61) and women (HR = 1.28, 95% CI: 1.08–1.51) in Cox proportional hazard model adjusting for confounders. In addition, there was a dose–response association between the severity of depressive symptoms and MCI incidence in total population, people aged ≥70 years and women (p-trend <0.001).
Conclusions
Significant depressive symptoms were associated with higher incidence of MCI in a dose–response fashion, especially among people aged 70+ years and women. Treating depressive symptoms targeting older population and women may be effective in preventing MCI.
For
$n\geq 3$
, let
$Q_n\subset \mathbb {C}$
be an arbitrary regular n-sided polygon. We prove that the Cauchy transform
$F_{Q_n}$
of the normalised two-dimensional Lebesgue measure on
$Q_n$
is univalent and starlike but not convex in
$\widehat {\mathbb {C}}\setminus Q_n$
.
This paper studies asymptotic properties of a posterior probability density and Bayesian estimators of spatial econometric models in the classical statistical framework. We focus on the high-order spatial autoregressive model with spatial autoregressive disturbance terms, due to a computational advantage of Bayesian estimation. We also study the asymptotic properties of Bayesian estimation of the spatial autoregressive Tobit model, as an example of nonlinear spatial models. Simulation studies show that even when the sample size is small or moderate, the posterior distribution of parameters is well approximated by a normal distribution, and Bayesian estimators have satisfactory performance, as classical large sample theory predicts.
To investigate the knowledge, attitudes and practices (K-A-P) about food safety and nutrition in Chinese adults who were recruited to the online survey during the epidemic of corona virus disease 2019 (COVID-19).
Design:
Participants were recruited by an online snowball sampling method. An electronic questionnaire was sent to our colleagues, students, friends, other professionals and their referrals helped us recruit more participants. The questionnaire included socio-demographic information, the attention paid to COVID-19, K-A-P about food safety and nutrition. Multiple and logistic regression analyses were used to explore related factors of K-A-P.
Subjects:
Totally, 2272 participants aged 24·09 ± 9·14 years, from twenty-seven provinces, autonomous districts or municipalities, with 18·3 % male and 83·4 % with a medical background.
Results:
The total possible knowledge score was 8·0, the average score was 5·2 ± 1·6 and 4·2 % obtained 8·0. The total possible attitudes score was 8·0, the average score was 6·5 ± 1·4 and 36·1 % obtained 8·0. The total possible food safety practices score was 5·0, the average score was 3·7 ± 1·0 and 20·7 % obtained 5·0. During this public emergency, 79·4 % participants changed diet habits, including increasing vegetables, fruit and water intake and reducing sugary drinks and snacks. Gender, age, educational and professional background, disease history, the attention paid to COVID-19 and related knowledge were associated with K-A-P.
Conclusion:
There was room for the improvement of K-A-P in participants during this public health emergency and further strengthening education about food safety and nutrition is needed. Findings indicate that education should address biased or misleading information and promote nutritious food choices and safe food practices.
Intestinal barrier inflammatory damage is commonly accompanied by hypoxia. The hypothesis that dietary Acanthopanax senticosus polysaccharides (ASPS) might modulate the hypoxia-inducible factor-1α (HIF-1α) signalling pathway and contribute to attenuate intestinal injury was tested in lipopolysaccharide (LPS)-challenged piglets. Thirty-six weaned pigs were randomly allocated to one of the following three groups: (1) basal diet + saline challenge; (2) basal diet + LPS challenge; (3) basal diet with 800 mg/kg ASPS + LPS challenge. LPS was injected at 15, 18 and 21 d, and intestinal sections were sampled following blood collection at 21 d . The results showed ASPS reversed (P < 0·05) LPS-induced decrease in average daily feed intake and rise (P < 0·05) of diarrhoea incidence and index. Biochemical index reflecting gut barrier damage and function involving ileal pro-inflammatory cytokines (TNF-α and IL-1β) and enzyme activity (diamine oxidase and lactase), as well as circulatory d-xylose, was normalised (P < 0·05) in LPS-challenged piglets receiving ASPS. ASPS also ameliorated intestinal morphological deterioration of LPS-challenged piglets, proved by elevated ileal villus height (P < 0·05) and improved appearance of epithelial villus and tight junction ultrastructure. Moreover, ASPS prevented LPS-induced amplification of inflammatory mediators, achieved by depressed ileal mRNA abundance of TNF-α, inducible NO synthase and IL-1β concentration. Importantly, ileal protein expressions of HIF-1α, cyclo-oxygenase-2 (COX-2) and NFκB p65 were also suppressed with ASPS administration (P < 0·05). Collectively, these results suggest the improvement of mucosal inflammatory damage and diarrhoea in immune stress piglets is possibly associated with a novel finding where HIF-1α/COX-2 pathway down-regulation is involved in NFκB p65-inducible releasing of inflammatory cytokines by dietary ASPS.
True ileal digestibility (TID) values of amino acid (AA) obtained using growing rats are often used for the characterisation of protein quality in different foods and acquisition of digestible indispensable amino acid scores (DIAAS) in adult humans. Here, we conducted an experiment to determine the TID values of AA obtained from nine cooked cereal grains (brown rice, polished rice, buckwheat, oats, proso millet, foxtail millet, tartary buckwheat, adlay and whole wheat) fed to growing Sprague–Dawley male rats. All rats were fed a standard basal diet for 7 d and then received each diet for 7 d. Ileal contents were collected from the terminal 20 cm of ileum. Among the TID values obtained, whole wheat had the highest values (P<0·05), and polished rice, proso millet and tartary buckwheat had relatively low values. The TID indispensable AA concentrations in whole wheat were greater than those of brown rice or polished rice (P<0·05), and polished rice was the lowest total TID concentrations among the other cereal grains. The DIAAS was 68 for buckwheat, 47 for tartary buckwheat, 43 for oats, 42 for brown rice, 37 for polished rice, 20 for whole wheat, 13 for adlay, 10 for foxtail millet and 7 for proso millet. In this study, the TID values of the nine cooked cereal grains commonly consumed in China were used for the creation of a DIAAS database and thus gained public health outcomes.
Measurement of runaway electron beam (REB) is essential to investigate behavior of runaway electrons produced in nanosecond-pulse gas discharge. A Faraday cup is designed to measure the REB current in nanosecond-pulse discharge when the applied dV/dt is 75 kV/ns. The Faraday cup considers the impendence match with the oscilloscope and the design of the receiving part. The experimental results show that the measured REB current has a rise time of 348 ps and a full width at half maximum of 510 ps. The comparison of the measurement results by the Faraday cup and a REB collector confirm that the Faraday cup is able to measure REB current in nanosecond-pulse discharge. Furthermore, consecutive waveforms of the REB currents show stable results by using the designed Faraday cup. In addition, effects of the interelectrode gap, gas pressure, and cathode material on the REB current are investigated by the designed Faraday cup, and the measurement results provide characteristics of REB current under different conditions. The REB current decreases when the gap spacing or gas pressure increases. REB current increases with the cathode diameter. It indicates that the high-energy electrons are generated not only at the edge of the cathode but also on the side surface of the cathode.
In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed. On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a laser-driven strong magnetic field up to 200 T has been achieved. The experiment was performed to model the interaction of solar wind with dayside magnetosphere. Also the low beta plasma magnetic reconnection (MR) has been studied. Theoretically, the model has been developed to deal with the atomic structures and processes in strong magnetic field. Also the study of shock wave generation in the magnetized counter-streaming plasmas is introduced.
Postnatal rapid growth by excess intake of nutrients has been associated with an increased susceptibility to diseases in neonates with intra-uterine growth restricted (IUGR). The aim of the present study was to determine whether postnatal nutritional restriction could improve intestinal development and immune function of neonates with IUGR using piglets as model. A total of twelve pairs of normal-birth weight (NBW) and IUGR piglets (7 d old) were randomly assigned to receive adequate nutrient intake or restricted nutrient intake (RNI) by artificially liquid feeding for a period of 21 d. Blood samples and intestinal tissues were collected at necropsy and were analysed for morphology, digestive enzyme activities, immune cells and expression of innate immunity-related genes. The results indicated that both IUGR and postnatal nutritional restriction delayed the growth rate during the sucking period. Irrespective of nutrient intake, piglets with IUGR had a significantly lower villous height and crypt depth in the ileum than the NBW piglets. Moreover, IUGR decreased alkaline phosphatase activity while enhanced lactase activity in the jejunum and mRNA expressions of Toll-like receptor 9 (TLR-9) and DNA methyltransferase 1 (DNMT1) in the ileum of piglets. Irrespective of body weight, RNI significantly decreased the number and/or percentage of peripheral leucocytes, lymphocytes and monocytes of piglets, whereas the percentage of neutrophils and the ratio of CD4+ to CD8+ were increased. Furthermore, RNI markedly enhanced the mRNA expression of TLR-9 and DNMT1, but decreased the expression of NOD2 and TRAF-6 in the ileum of piglets. In summary, postnatal nutritional restriction led to abnormal cellular and innate immune response, as well as delayed the growth and intestinal development of IUGR piglets.
The etiology and pathogenesis of neurodegenerative disorders has yet to be elucidated, so their differential diagnosis is a challenge. This is especially true in differentiating Alzheimer's disease (AD), dementia with Lewy bodies (DLB), Parkinson disease (PD), and multiple system atrophy (MSA).
Methods:
A total of 11 eligible articles were identified by search of electronic databases including PubMed, Springer Link, Elsevier, and the Cochrane Library, up to June 2014. In meta-analyses, standardized mean differences (SMD), with 95% confidence intervals (CI), comparing cerebrospinal fluid (CSF) measures of α-synuclein between the above conditions were calculated using random-effects models.
Results:
CSF α-synuclein concentrations were significantly higher in AD compared to DLB [SMD: 0.32, 95% CI: (0.02, 0.62), z = 2.07, P = 0.038]; PD [SMD: 0.87, 95% CI: (0.15, 1.58), z = 2.38, P = 0.017]; or MSA [SMD: 1.14, 95% CI: (0.15, 2.14), z = 2.25, P = 0.025]. However, no significant difference was found between patients with AD and neurological cognitively normal controls [SMD: 0.02, 95% CI: (−0.21, 0.24), z = 0.13, P = 0.894].
Conclusions:
Results of these meta-analysis suggest that quantification of CSF α-synuclein could help distinguish AD from other neurodegenerative disorders such as DLB, PD, or MSA.
The present study was conducted to investigate the effects of chitosan (CS)-Zn on intestinal morphology, mucosal epithelial cell apoptosis and mucosal immune function in weanling pigs. A total of 150 weanling barrows with a body weight of 7·2 kg were randomly allocated into five groups. A basal diet without Zn supplementation was used as the control and other four groups were fed the control diet supplemented with 50 or 100 mg/kg of Zn as CS-Zn, 100 mg/kg of Zn as ZnSO4 and 3000 mg/kg of Zn as ZnO, respectively. The feeding trial lasted for 28 d. The results showed that serum diamine oxidase activities, d-lactate levels and endotoxin contents were lower in pigs fed dietary 100 mg/kg of Zn as CS-Zn or 3000 mg/kg of Zn as ZnO than in pigs fed the control or 100 mg Zn/kg as ZnSO4 diet. The ratios of the villus height:crypt depth of the duodenum, jejunum and ileum were higher in pigs that received 100 mg/kg of Zn as CS-Zn or a high level of Zn as ZnO than in pigs fed the control diet. Moreover, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL)-stained ileal epithelial cells were found in the control group, and apoptotic cells did not appear prominently in pigs that received the 100 mg/kg of CS-Zn or ZnO diet. Secretory IgA concentration in ileal mucus was increased in the dietary group that received 100 mg/kg of CS-Zn or ZnO. These results indicated that dietary 100 mg CS-Zn/kg had similar biological effects to dietary 3000 mg ZnO/kg on intestinal morphology, mucosal epithelial cell apoptosis and mucosal immune function.
We conducted an interview survey around and within Mengla and Shangyong Nature Reserves, Mengla County, Yunnan, China, in December 2008 to ascertain whether gibbons were present in the area, and in December 2011 we surveyed two sites in the Reserves for the northern white-cheeked gibbon Nomascus leucogenys. We found no signs of the existence of gibbons during the survey. Illegal hunting was common at both sites. Only 36 individuals in nine groups were recorded in Mengla and Shangyong Nature Reserves in the 1980s, and this small and fragmented population was probably unable to survive the pressure of hunting. No white-cheeked gibbon was recorded in Huanglianshan Nature Reserve in a survey carried out by other researchers in 2003. Gibbons have a very low chance of survival in unprotected forest, and we conclude that the white-cheeked gibbon is extinct, or at least ecologically extinct, in China.
Compound effects of B and Y additions on the microstructures and properties of a new type of high-strength and high-conductivity (HSHC) Cu–Mg–Te alloys are investigated on the aspects of purification and precipitation. Because of the purification function of B and Y additions, the tensile strength increased superlatively by the amplitude of 21.7% with a similar increase of elongation and the electrical conductivity of 4.2%. By comparison of the calculated decomposition pressures of B2O3 and Y2O3 at different temperatures, it can be concluded that the boron oxide is more stable than the yttrium oxide in the copper liquid, indicating the superior deoxygenization purification of the rare earth yttrium. The dispersive distribution of the Y–B compounds (YB6) was another factor for the improvement of the mechanical properties of the copper alloy. Finally, the copper alloy treated by hot rolling, cold rolling, and annealing processes in sequence exhibits HSHC with the tensile strength of 610.7 MPa and the electrical conductivity of 53.1%IACS.
Intra-uterine growth-retarded (IUGR) neonates have shown an impairment of postnatal intestinal development and function. We hypothesised that the immune function of IUGR neonates might be affected by increased nutrient intake (NI) during the suckling period. Therefore, we investigated the effects of high NI (HNI) on the growth performance, intestinal morphology and immunological response of IUGR and normal-birth weight (NBW) piglets. A total of twelve pairs of IUGR and NBW piglets (7 d old) were randomly assigned to two different nutrient-level formula milk groups. After 21 d of rearing, growth performance, the composition of peripheral leucocytes, serum cytokines and intestinal innate immune-related genes involved in the Toll-like receptor (TLR)-4–myeloid differentiation factor 88–NF-κB pathway were determined. The results indicated that IUGR decreased the average daily DM intake (ADMI) and the average daily growth (ADG). However, the ADMI and ADG were increased by HNI, irrespective of body weight. Likewise, serum cytokines (TNF-α and IL-1β) and ileal gene expressions (TLR-4, TLR-9, TRAF-6 and IL-1β) were lower in IUGR piglets, whereas HNI significantly increased blood lymphocyte percentage and serum IL-10 concentrations, but decreased neutrophil percentage, serum IL-1β concentrations and ileal gene expressions (NF-κB and IL-1β). Furthermore, IUGR piglets with HNI exhibited lower serum concentrations of TNF-α and IL-1β than NBW piglets, and these alterations in the immune traits of IUGR piglets receiving HNI were accompanied by decreasing ileal gene expressions of TLR-4, TLR-9, NF-κB and IL-1β that are related to innate immunity. In conclusion, the present findings suggest that increased NI during the suckling period impaired the immune function of neonatal piglets with IUGR.
Anodically formed TiO2 nanotube arrays composed of the anatase phase with periodically modulated diameters (PMTiNTs) are excellent photocatalysts for the sunlight-driven transformation of carbon dioxide into hydrocarbons. Exploiting the full potential of this nanoarchitecture for CO2 photoreduction requires integration with metal nanoparticles that function as catalytic promoters for multistep electron transfer reactions. We studied the effect of different metallic and bimetallic nanoparticles on the rate of generation of light hydrocarbons by the photoreduction of CO2. All the metal nanoparticles were loaded on to the TiO2nanotubes using the technique of photodeposition, which standardized the coating process and enabled examination purely of the effect of different metals. Photodeposition was used not only due to its simplicity but also because it enabled us to engineer very fine coatings possessing excellent uniformity and depth penetration into the nanotubes. The best performing co-catalysts were found to be CuPt (atomic ratio of 0.33:0.67), Pt and NiPt (1:2), which when loaded onto the PMTiNTs yielded total hydrocarbon generation rates of 3.5, 0.85 and 0.8 mL g-1 hr-1 respectively. The time required to form PMTiNTs was reduced by a factor of 160 by using a recently reported recipe based on fluoride ion bearing electrolyte containing lactic acid. PMTiNTs formed using the ultrafast growth lactic acid-based electrolytes exhibited similar photocatalytic properties to samples obtained more slowly using conventional ethylene glycol-based electrolytes.
Based on 187 galaxy clusters identified from the photometric redshifts of galaxies in the Cosmic Evolution Survey (COSMOS) field(Wen & Han 2011), cluster galaxies brighter than MV = -20.5 are classified into four categories according to their best-fitting templates of the spectral energy distributions (SEDs) provided by Ilbert et al. (2009): early-type (including elliptical and lenticular) galaxies (E+S0), spiral galaxies (S), irregular galaxies (Irr), and starbursts (SB). The fractions of these four SED types are presented as the functions of redshift in Figure 1. Fraction of each category varies remarkably with cluster redshift: fractions of normal galaxies (E+S0+S+Irr) tend to decrease with redshift, whilst the starburst proportion tends to increase with redshift. For the normal galaxies, there exists a sequence for the decreasing slopes of morphological fractions. Majority of the galaxies in high-redshift clusters (z > 1.0) are experiencing strong star-formation activities, which leads to a very high proportion of starburst.
Thermoelectric modules are of great interest for power generation applications where temperature gradients of approximately 500K exist, and hot side temperatures near 800K. The fabrication of such modules requires optimization of the material compositions, low contact resistivities, and low thermal loss.
AgPbmSbTe2+m (LAST) and Ag(Pb1-xSnx)m SbTe2+m (LASTT) compounds are among the best known materials appropriate for this temperature range. Various measurement systems have been developed and used to characterize bulk samples in the LAST and LASTT systems within this operating temperature range. From the characterized data, modeling of modules based on these materials and segmented legs using LAST(T) with Bi2Te3 have been used to identify the optimal geometry for the individual legs, and the length of the Bi2Te3 segments. We have segmented LAST(T) with Bi2Te3 and achieved contact resistivities of less than 10 μΩ•cm2.
Here we give a detailed presentation on the procedures used in the fabrication of thermoelectric generators based on LAST, LASTT, and segmented with Bi2Te3 materials. We also present the output data on these generators.